Weighing as much as a small car, a rover named Curiosity rolls quietly around Mars.

Scientific instruments pack its body and cluster at the end of a mechanical arm.

An arrangement of lenses and instruments tops its mast, like a face.

To the many NASA workers involved in Curiosity's mission on Mars, the rover is not simply a robot, but an astronaut bravely exploring an alien place.

Curiosity's instruments collect data and its cameras take images of the Mars landscape, including self-portraits, in vivid color and detail.

As it roams and explores, Curiosity will help find the answers to such age-old questions as has there ever been life on Mars?

Could there be one day?